Timing device



March 24, "1942. M D, MCARTY 2,277,521

TIMING DEVICE Filed Oct. 29, 1938 3 Sheets-Sheet 1 March 24, 1942. D McCARTY TIMING DEVICE Filed Oct. 29, 1958 3 Sheets-Sheet 2 March 24, 1942. MQDMCCAR Y' 2,277,521

TIMING DEVICE Fil ed Oct. 29, 1938 5 Sheets-Sheet 5 have not proven entirely satisfactory,

Patented Mar. 24,? 1942 UNITED STATES PATENT OFFICE TIMING DEVICE Malcolm -D. McCarty, Dallas, Tex., assignor, by

mesne assignments, to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York Application October 29,,1938, Serial No. 237,79

2 Claims.

This invention relates generally to electric means for placing timing indications on the seismogram simultaneously with the recording of signals which have been generated in sympathy with seismic waves.

Many methods and arrangements of apparatus have been used heretofore by those conducting seismic surveys for this purpose, but these Objections have arisen to these methods because they necessitate the introduction of spurious currents into the vicinity of the recording galvanometer circuits which by electric coupling would induce currents in the circuits of the galvanometer. that would be objectionable when recorded on the seismogram in that they tend to obscure the signals from which it is desired to take the survey data.

Therefore, it is the primary object of this invention to provide means that will place indications of timeon the seismogram with a high degree of accuracy without introducing into the' galvanometer circuits spurious currents which would tend to obscure the signals that are being recorded on the traces of the seismogram.

Another object of this invention resides in the provision of electromagnetic power meansfor driving a reed at a definite frequency that has attached thereto a shutter adapted to intercept a beamof light which is being projected on a moving photographic film.

This invention further contemplates a compact unit in which the lamp housing and mount therefor, as well as the power means and vibrating reed, are mounted in operative position on a single base.

Other objects and advantages of this invention will become apparent from the following description when considered with the accompanying drawings, in which:

Fig. l is a diagrammatic view of a recording galvanometer showing the timing device forming the subject matter of this application in op- .erative position;

Fig. 2 is a detailed plan view partly in section of the timer;

Fig. 3 is a detailed vertical sectional view of the timer taken along the line 33 of Fig. 2;

Fig. 4 is a vertical sectional view of the timer taken along the line 4-4 of Fig. 2 showing the lamp housing;

Fig. 5 is 'a vertical sectional view of the magnetic driving means taken along the line 5-5 of Fig. 2;

\ seismographs, and particularly to a method and v Fig. 6 is a cross-sectional view of the base showing the mount for the vibrating reed;

Fig. 7 is a perspective view of the soft iron spacer which receives the fin attached to the vibrating reed and which also forms a part of the magnetic path for the flux which drives the reed;

Fig. 8 is a perspective view of one element of the timer base by means of which the reed and its associated elements are made vertically adjustable; and

Fig. 9 is a perspective view of a second adjusting element forming a part of the base.

Referring to the drawingt, particularly Fig. 1, there is shown diagrammatically a recording galvanometer having the timing device forming the subject matter of this application incorporated therein. In thisfigure, i represents a conventional photographic camera of the moving film or sensitized paper type.- The film or paper 2 is fed through the drum 3 over the rollers 4, where it is exposed, and around the drum 5. The traces are exposed on this paper by means of the optical system shown comprising the source of light or lamp 6, small mirrors on the vibrating elements within the housing 1, and the lens 8. Simultaneously with the exposure of the traces, transverse timing lines are placed on the film or paper by means of the timing device 9 and its adapted to support the lamp housing l6. Lamp housing I6 is formed by a cylinder I! having closures I8 and i9 fitted in either end thereof.

Closure l8 which is in the form of a plug has made integrally therewith or suitably attached to it a lamp socket I9 adapted to receive a lamp 20. .The cylinder I1 is provided with anarrow slot 2| through Which'the light from the lamp 20 passes. Plate 22 having an aperture of predetermined size is adjustably secured in position over the opening 2| in the lamp housing by means of bolts or screws 23. In this manner a beam of opening or slot 25 through which the beam of light passes. Secured to the bottom of the reed II is a fin 26 of some high permeability metal. Vibrations of the reed II are sustained by the action of the magnetic flux produced in the core 21 by apulsating current that flows'in the coil 28. Any conventional frequency generator shown diagrammatically at 29 in Fig. 2,may be used to generate the pulsating current as long as its frequency can be controlled accurately. The coil 28 is made up of two windings, each of which surrounds the core 21. These windings are spaced from each other by a soft iron spacer member 30 that is secured to the center of the core 2'! in conductive relationship with it. Spacer member 30 as shown in Fig. 7 is provided with a slot 3| in which the fin 26 is adapted to vibrate. Coil 28 is completely enclosed in an iron cylinder 29a and its end plates 30a and 3|a. En-

closing the coil in this manner prevents stray magnetic fluxes from inducing currents in the adjacent circuits of the galvanometer. The coil housing is mounted upon an adjustable base 32 by means of the end plates 30 and 3|. The adjustable base 32 which, although shown made of two pieces, could obviously'be made from a single piece of metal. As shown in Fig. 3, the adjustable base is substantially wedge-shaped and is held in position on the base l3 by means of the retaining bars 33 and 34 and the screws 35 and 35. Interposd between the adjustable base and the base plate I3 is a second wedge-shaped member 3'! that is adapted to be moved relative to the base plate l3 and the adjustable base 32 by means of the screw 36. Movement of the wedgeshaped member 31 when the screws 35 are loosened will cause the coil housing and reed to move vertically to effect an adjustment relative to the light beam. As shown in Fig. 2, a binding post panel 38 is mounted on the edge of the base plate binding posts so that are connected to the coil 26 are adapted toreceive conductors from a. frequency generator 29 which may be of conventional type that will supply the coil 26 with the necessary alternating or pulsating current to drive the reed ll.

I3. On this binding post panel are disposed four 7 binding posts 39, two of which are connected to the coil. 26 while the other two are connected to the lamp socket I9 in the lamp housing IT. The

In operation, the pulsating or alternating current as supplied to the coil 26 by the frequency generator induces in the core 21 and the spacer member 30 alternating magnetic fluxes which will alternately attract and repel the fin 24 to drive the reed II that carries the timing shutter I2 at the frequency of the frequency generator. The amplitude of vibration of the reed I I can be controlled by an increase or decrease in the amplitude of the current that is being supplied to the coil 26.

I claim:

1. In an electric timing device for oscillographs, a vibrating element, a thin armature supported on the moving end of said vibrating element parallel to theplane of vibration of said element, a disk-shaped member provided with a slot intermediate the peripheral edges thereof in which a portion of said armature moves during vibration of said element, at least one coil coaxial with said disk-shaped member, and means completing a magnetic circuit about said coil at each side of said disk-shaped member from the center to the periphery thereof.

2. In an electric timing device for oscillographs, a vibrating element, a thin armature supported on the moving end of said vibrating element parallel to the plane of vibration of said element, a disk-shaped member provided with a slot intermediate the peripheral edges thereof in which a portion of said armature moves during vibration of said element, a plurality of coils coaxial with said disk-shaped member, and means completing a magnetic circuit about said coils at each side of said disk-shaped member from the center to the periphery thereof.

MALCOLM D. MCCARTY. 

